Maybe a long shot, but I've had this thing kicking around the shop for awhile and not sure what kind of vise it came off of. The thread is 1" OD with 3.5 TPI Acme (7 threads per 2"). I'm curious if the odd thread would help to ID it? First picture is how it started, 2nd picture is after it took a trip through the chemical rust remover barrel and was polished with a wire wheel. I guess first I'd be curious if it would help anyone repairing an old vise (why I want to ID it), and if not that I hope to find or machine a bronze or iron nut to fit it and make a custom wood vise with it.
Find an oil field machine shop . One with manual lathes . A good lathe operator can machine a new nut for you. A friend of mine made a new screw and nut for a post vise that has been in our farm shop since it was set in cement 60 years ago.
I work in a machine shop and am planning on making the nut myself, though the odd thread will be tricky. If I can ID the original vise though I might be able to find an old moving jaw that I can cut the nut out of and save some labor.
Use a small boring bar and take lots of light cuts and several clean up passes to prevent the boring bar deflection
3.5TPI is an unusual pitch for ACME thread. It's a little bit over 7mm thread pitch - could be 7mm depending on how accurate you are measuring. Any chance this is a metric screw thread? Cheers, Harv
I doubt it as other features are nice round fractional numbers. Some spots along the thread have more wear than others, but checking at various spots along the length I'm confident it's 3.5 tpi. I've single point threaded some male acme threads before, but this will be my first acme nut. I checked tonight and fortunately one of my lathes has the thread option, the 1909 16x8 Hendey. I want to make the rest of the vise first before delving into making the nut. It would probably be easier to get off-the-shelf acme, but then again I could just buy a vise. I'm mainly trying to keep the old screw out of the scrap pile. If it's no use in it's original capacity, then I'm using it as an excuse to make a wood vise, which I'm thinking will be a standard under bench wood working type, but with jaws that extend to the sides a bit more than typical, and I want to make it with jig holes around the perimeter for clamping odd shaped pieces. The jaws will just be welded steel plate.
When cutting an acme thread I've first cut to finished depth a V-thread, which makes the cut with the acme tool much easier.